Byronlj, that's interesting and hadn't thought of it that way...so the sending unit is actually measuring back pressure at the filter? Low a less restrictive filter produces a lower gauge reading....hmmm....would make sense.
Ben, that's funny! When they first started emissions checks in NY years ago, we used to do the same thing....run the tank almost empty and put in 3 or 4 cans of STP Dry Gas, the engine was practically running on alcohol and burning clean! Here in KY, they repealed the safety inspection requirement, forget about emissions....
Geotex, you got me...I know the old Sub forum is all but dead. I can think of a few names but none from NJ, that's what's throwing me...but you're a fellow L18 owner!